posted on Mar, 5 2013 @ 02:48 PM
reply to post by Druscilla
Interesting thread, thanks for the finding!
Direct data can be seen on the JPL Small-body Database
Also, there are regularly updates on SpaceObs.org site
with the following comments written three days ago:
After adding the recent measurements, taken by Tomas Vorobjov at Kitt Peak Observatory (March 1, 2013), the distance of closest approach increased
to 0.00047 AU (70 500 km). CA time is October 19, 2014, 19:09:24.48 UT. I think what we can fairly accurately estimate these parameters, before the
temporary pause in the observations of this comet, due to it’s low elongation.
And this one written two days ago:
Initially the calculation was based on the recent observations known for me, including observations by ISON-NM observatory (Feb. 27), Martin
Mašek (Feb. 27) and Tomas Vorobjov (March 1). Estimation was made on a sample of 1,000 virtual particles (clones), calculated by the Monte-Carlo
method and based on the nominal orbit solution. Calculation shown what only 2 of 1,000 clones will collide with Mars, i.e. 0.2%.
Late at night, we received information what found two another archival observations (October 4, 2012) by Pan-STARRS. Now, arc of observations
increased to 148 days! Based on the new data, calculations was restarted again. The collision probability decreased in 2.5 times. Neither clone from a
sample of 1,000 virtual particles not collided with Mars. Final calculation is based on a sample of 10,000 clones! It shown that only 8 virtual
objects will be collide with the Red Planet, i.e. probability of this event fell from 0.2% to 0.08%, but still high enough for the events of such
scale. Minimal distance of close approach, according nominal orbit solution is 0.00039 AU or ~58,000 km.
Check out as well Emily Lakdawalla blog
she gives some very good informations about the upcoming event, with some interesting links to read and diagrams, like this one:
C/2013 A1 (Siding Spring) will pass extremely close to Mars on October 19, 2014. This orbital diagram was based on slightly older
observational data that showed the closest approach happening on October 20. The comet will be coming up from south of the ecliptic in a direction
opposite to that of Mars'. (The orbits are drawn in dark colors where they dip below the ecliptic, and bright colors when they rise above the
ecliptic. Since Earth's orbit is, by definition, in the ecliptic, its orbit is bright everywhere.)
What it could looks like from Mars ground:
At the actual estimated distance, if not hitting Mars, coma's comet will pass through the planet, with all the possible damages for the rovers, let
alone the amazing show that it will be!
edit on 5-3-2013 by elevenaugust because: (no reason given)